<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>08 百度换肤</title>
    <style type="text/css">
        *{
            padding: 0;
            margin: 0;
        }

        ul{
            list-style: none;
        }
        #skin{
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-image: url('images/skin1.jpg');
            background-position: center 0;
            background-repeat: no-repeat;
        }
        #skin-photo{
            width: 100%;
            height: 100px;
            position: relative;
            z-index: 10
        }
        #skin-photo ul{
            overflow: hidden;
            width: 1200px;
            margin: 0 auto;
            background-color: rgba(255,255,255,.5);
        }
        #skin-photo ul li{
            float: left;
            cursor: pointer;
            height: 120px;
            margin: 10px 0 10px 96px;
        }
        #skin-photo ul li img{
            width: 180px;
            height: 120px;
        }
    </style>
</head>
<body>
    <div id="skin"></div>
    <div id="skin-photo">
        <ul>
            <li>
                <img src="images/skin1.jpg">
            </li>
            <li>
                <img src="images/skin2.jpg">
            </li>
            <li>
                <img src="images/skin3.jpg">
            </li>
            <li>
                <img src="images/skin4.jpg">
            </li>
        </ul>
    </div>
    <script type="text/javascript">
        // 1.获取对应的图片
        var skin = document.getElementById('skin');
        var allItems = document.getElementByTagName('li');
        for(var i = 0; i < allItems.length; i++){
            allItems[i].index = i + 1;
            allItems[i].onclick = function(){
                skin.style.backgroundImage = `url('images/skin${this.index}.jpg')`
            }
        }

    </script>
</body>
</html>